This research combines medical and engineering programs at Riverside Research Insitute and Columbia University to study the alterations which can be induced in ocular tissues by high intensity ultrasound. The objectives of the research are twofold. The first objective is to provide the knowledge and practical means for applying ultrasound as a therapeutic modality in ophthalmology. The second objective is to acquire the data base and understanding needed to assure the continued safety of ultrasonic diagnosis in ophthalmology. A therapeutic ultrasound system will be designed and implemented to provide stable repeatable exposures over small well-defined volumes. It has been coupled with a diagnostic ultrasound visualization system to enable accurate insonification of target tissues regardless of the optical status of the media. Therapeutic applications will be investigated on in vitro and in vivo animal models as a prelude to human insonification. The potential for this modality in treatment of ophthalmic disorders includes disruption and dispersion of vitreous hemorrhages and membranes, creation of chorioretinal lesions to repair detached retinas or coagulate abnormal vasculature, and destruction of ocular tumors. The effect of this ultrasound modality on tissues will be studied by indirect ophthalmoscopy, fundus photography and diagnostic ultrasonography, and histologically by light and electron microscopy. Knowledge gained concerning fundamental mechanisms of tissue-ultrasound interactions will insure the safety of the intended therapies, as well as the continued safe application of low intensity diagnostic ultrasound.